If a client has purchased a Pro Pack, but can't access the new Features in WIT, the chances are that their WIT item has been processed as an additional item rather than as the catalogue item.
You can check this by writing a script and looking in the Dat_Order_Lines_Catalogue_Items table for the company and survey in question. If there is no WIT Pack in this table, then you can change your query to look in the Dat_Additional_Items table.
Where there is an additional item for a WIT Pack, you will need to change the order so that it is pointing at a catalogue item instead, and also add the WIT Features into Dat_Company_Survey_Wit_Features too.
To guide you in the right direction, you can search in the schema solution for a previous schema change to resolve this issue.